[CastleBravo]

Hi,
Picked up my first N54 this week in a 2010 135i. Just getting to grips with whats what but I can't seem to find a good drawing of the stock PCV setups.

It's a low mileage motor 62k but I want to essentially overhaul and do everything 'right'. The PCV system has not been a particular point of pain on previous or current BMWs I've owned so really all the woe around this system is making me want to really understand what is going on with it.

Thanks in advance.

[eaton18spd]

The pcv system on this engine is pretty much all contained in the valve cover, including the valve. The valve is only replaceable by upgraded aftermarket part. There is also a check valve hose that plugs into the back of the valve cover from the pcv valve and then goes to the rear inlet, this hose is replaceable. Also, there are ports that pass through the top of the head, you can see the ports with the valve cover removed, they pass through to the intake ports and then into the valve cover. This can potentially get plugged along with the ports and passages in the valve cover.

[dmckmc]

See No. 3, Engine Mechanical here:

https://www.e90post.com/forums/showthread.php?t=38856


Full explanation with pics for Hi/Lo load situatinos.

[CastleBravo]

Thanks for the info. That's what I needed.

On further inspection and reading up on these some more it seems there is no need or indication to fully rebuild at this point. The intakes are fairly messy. I'm going to do a high and low side catch can setups and replace the check valves with an aftermarket version, and replace the valve cover gaskets (something I've spent the last 10 years doing on every BMW I've ever owned...the joys!), make sure there is a good seal there for the PCV.